Saudi Journal of Biological Sciences Vol. 15, No (1) June, 2008
Siddig El Tayeb Muneer
144
Council for Environment and Natural Resources,
Ministry of Environment and Development, Sudan.
Mekuria, M. and Waddington, S. 2004. Institutional and policy support is essential to promote the adoption of soil fertility technologies on maize-based smallholder farms in Southern
Africa. The 4
th
International Crop Science Congress. Brisbane,
Australia, 26 Sept. -1 Oct. 2004.
Njiti, C. F. and Galiana, A. 1996. “Symbiotic
properties and Rhizobium requirements for effective nodulation of five tropical dry zone acacias”. Agroforestry systems, Vol. 43:
265–275.
Olsson, L. and Ardo, J. 2002. “Soil carbon sequestration in degraded semiarid agro-ecosystems – perils and potentials”.
Ambio, Vol. 31: 471-477.
Place, F. 1995. The role of land and tree tenure on the adoption of agroforestry technologies in Uganda, Burundi, Zambia and
Malawi: A summary and synthesis. Madison, Wisconsin: Land
Tenure Center, University of Wisconsin.
Pretty, Jules N. 1998. Supportive policies for scaling up sustainable agriculture. In Roling, N. G. and Wagemakers, M. A. 1998
(eds.). Facilitating sustainable agriculture: 23 -45.
Cambridge University Press (U. K.).
Rainforests 2007. Sudan: Environmental profile. http://rainforests.
mongabay.com/20somaliasudan.htm Rogers, Everett M. 1993.
Diffusion of innovations (4
th
Edition). New York: The Free
Press.
Roling, N. G. and Wagemakers, M. A. 1998. A new practice:
Facilitating sustainable agriculture. In Roling, N. G. and
Wagemakers, M. A. 1998 (eds.). Facilitating sustainable agriculture: 3 - 22. Cambridge University Press (U. K.).
Sharma, Arun K. (No Date). Arid Zone Agroforestry: Dimensions and Directions for Sustainable Livelihood. Jodhpur (India):
Central Arid Zone Research Institute.
Wikipedia (the free encyclopedia) 2008. Agrofroestry. htt://
en.wikipedia.org/wiki/Agroforestry.
World Agroforestry Centre 2007. Annual Report 2006: Tackling
Global Challenges through Agroforestry. Nairobi (Kenya):
World Agroforestry Centre.
Tisdell, Clem. 1999. Conservation farming and indicators of agricultural sustainability. In Dragun, Andrew K. and Tisdell,
Clem 1999 (eds.): Sustainable agriculture and environment:
57 – 78. Edward Elgar Publishing Limited (UK).
Saudi Journal of Biological Sciences Vol. 15, No (1) June, 2008 145
Share with your friends: